“Travel is fatal to prejudice, bigotry, and narrow-mindedness” -- Mark Twain, "Innocents Abroad."
Or, sometimes, if one doesn't probe deep enough, travel can reinforce stereotypes. In some societies, especially those with lots of "guest workers" where your passport pre-determines how much money you make and your station in life, and people generally live in segregated compounds based on nationality, one has to make a special effort to see beyond stereotypes. The default position is to think of certain nationalities as the "servant classes," and certain nationalities as the "ruling classes." And yet, paradoxically, "guest workers" in wealthy countries who send money back home are viewed by their compatriots as having escaped the economic confinements of home for adventure and success abroad.